Apparatus for operating drawers or the like in a desk, cabinet or the like



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APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet I.

1961 o. A BECKER 3,005,672

APPARATUS FOR QPERATING DRAWERS OR THE LIKE IN A DESK. CABINET OR THE LIKE Filed April 9, 1958 '7 Sheets-Sheet 2 Oct. 24, 1961 o. A BECKER 3,005,672

APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet 3 1961 o. A BECKER 3,005,672

APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet 4 a 177W ALF/65.0 556/5? 7 W a Oct. 24, 1961 O. A APPARATUS FOR .OPER

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ATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet 5 JV W,%

Oct. 24, 1961 o. A BECKER 3,005,672

APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet 6 IN VEN TOR. 0770 flL/WED aim 5e Oct. 24, 1961 o. A BECKER 3,005,672

APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Filed April 9, 1958 7 Sheets-Sheet 7 United States Patent 3,005,672 APPARATUS FOR OPERATING DRAWERS OR THE LIKE IN A DESK, CABINET OR THE LIKE Otto Alfred Becker, Mainzer Strasse 201-209,

Saarbrucken 3, Saarland, Germany Filed Apr. 9, 1958, Ser. No. 727,320 Claims priority, application Germany Apr. 23, 1957 5 Claims. (Cl. 312-223) This invention is for improvements in apparatus for operating drawers or the like in a desk, cabinet or the like and is an improvement in or modification of the invention forming the subject of patent applications Serial No. 644,572 and 589,475, now Patent Nos. 2,946,637 and 2,873,159, respectively. An object of the invention is to provide operating mechanism for drawers or the like which is smooth and effective in operation.

When a drawer or the like in a desk or cabinet is acted on by operating means at one side only or the drawer or the like there is a tendency for jerky movement owing to the liability of an off centre force tending to jam the drawer by angular sideways motion. The impelled side or in case of stoppage the braked side of the drawer tends to move or stop more quickly than the other side owing to the inertia and kinetic energy of the other side, as the case may be. In case of stoppage the further the drawer or the like projects from its mounting the stronger is the sideways motion. The tendency for angular sideways motion is liable to give rise to premature wear and tear of the guiding elements.

In accordance with the invention there is provided apparatus for operating drawers or the like in a desk, cabinet or the like which is characterised by having each drawer or the like operable independently by means which applies approximately the same impelling or braking thrust to each side of the drawer or the like. The drawers may be operated on both sides simultaneously, but preferably it is arranged that the force of application of the motive or braking force is arranged to be in the neighbourhood of the Centre lines of the drawers or the like, conveniently below them. Accordingly a further feature of the invention is the provision of apparatus for operating drawers or the like characterised by having a separate drive arranged under the bottom of each drawer or the like by which each of them can be operated as desired independently of the movement or stationary position of any other drawer or the like. i

In one form of construction there is fixed longitudinally on the lower surface of each drawer ,or the like a separate driven member (e.g. a rack) running centrally which is engaged by a driving member (e.g. a toothed wheel mounted on a shaft) preferably disposed at the front end of the drawer mounting. The drawer is pulled out or pushed in according to the direction of movement of the driving member, e.g. rotation of the toothed wheel. These separate drives of the drawers can if desired be coupled to a motor drive by couplings which are preferably operated magnetically. It is convenient to employ a motor which is driven in one direction only and to determine by means of push-buttons whether the drive direction imparted to the drawers or the like is to be forward or reversed. For this purpose a reversing clutch is provided between the drawer-drives and the motor. It is thereby possible for two writing table housings and/or their drawers to be operated from a single motor drive simultaneously and independently of one another, for any movement-direction of any selected drawer at any time whatever the intermediate position or movement of any of the otherdrawers. This is par.- ticularly advantageous if two skilled workers, seated opposite each other, have to work at a common card index or record cabinet of this kind and one housing with 3,005,672 Patented Oct. 24., 1961 the drawers belonging to it is at the disposal of each of these workers.

It is furthermore advantageous to arrange separate brakes in connection with the drawer couplings which promptly stop the shaft on which the member driving the drawer is mounted at the instant of the release of the operating button. These brakes can be operated simultaneously with the drawer couplings.

The return of a drawer to its final position also presents difficulties. Neither a hard nor an elastic stop-bar is suitable. The drawer is thrown back a little bit by the impact and so the exact final position is not maintained. Also other disturbances of various kinds occur in connection with this. To avoid this defect the invention provides for the incorporation at the end of a buffer which gently absorbs the shock-impact of the drawer by the compression of air in a cylinder and thereby allows the air to escape through a regulatable vent in such a way that no recoil of the drawer ensues. In addition catches may be provided which fix the final position of the drawer.

In order to indicate the temporary positions of the drawers to facilitate stoppage in intermediate settings while they are being pulled out and pushed in, optical indicating means are preferably provided. These optical means may be divided to correspond with subdivisions of the drawerse.g. in compartments or card index groups-and the marking of these groups in alphabetical or numerical order may be identified by the indications of the optical means, e.g. by the lighting up of different electric bulbs associated respectively with the separate groups.

Both for pulling out and for pushing in drawers separate push buttons are conveniently provided for each drawer and these may be distinguished by optical means.

These and other improvements, including the restricted guidance of movements between a drawer and its extension carriage, and a yieldable mounting of the front of a drawer are incorporated in certain preferred constructions which are illustrated by way of example in the accompanying drawings and which will now be described with reference to the drawings.

FIG. 1 shows in broken perspective view the left side part of a desk having a pedestal 601 and push buttons 602, 603 for controlling the forward and backward movements of drawers 613, the push buttons being arranged in the table top. Beside them on the right are small openings 604 in the table top, the purpose of which is to make visible optical means provided below them. In line with the push buttons indicating openings 605 are provided for distinguishingbetween the forward and back-ward movement push buttons.

A motor .606 mounted rear wardly under .the desk top drives a chain 609 through a shaft .607 and a chain wheel 608, the chain serving to drive through a chain wheel 610 a shaft 611 carrying a cog wheel 612. The cog wheel 612 gears with a rack 614 fixed centrally and longitudinally on the lower surface of a drawer v613.

FIG. 2 shows diagrammatically the arrangement of a reverse gearing and clutch by which the unidirectional rotation of the motor 606 can, if desired, be transmitted in reverse for pushing back a drawer which has been pulled out. Two toothed wheels .616 and 617 are fixed on the motor driving shaft 615. The toothed wheel 617 is constantly engaged with a toothed wheel 618 which is freely rotatable on the shaft .607 and has a half coupling .619 fixed to it. .On the shaft 607 is fixed .a chain wheel 603 driving a chain 609. A coupling member slidhand coupling position in which the half couplings 619 and 623 engage with each other, whereby the motion of the wheel 618 is transmitted to the shaft 607. When the coupling is set in this way the drawer is pushed out. For the backward or pushing in movement of the drawers a reversing Wheel 628 is provided in return gearing on a separate shaft 629 and engages both with the wheel 616 and also with a freely turning wheel 627 on the shaft 607. A half coupling 626 is likewise fixed on wheel 627. With the help of an electromagnet 620 which is energized by the depression of one of the return push buttons 603 the gear shift fork 621 is moved against the action of the spring 622 into its right hand position so that the half couplings 625 and 626 engage with each other and the motion of the wheel 627 is transmitted to the shaft 607 whereby a backwards or pushing-in movement is given to the desired drawer.

FIG. 3 shows diagrammatically the arrangement of the drawer drive. The chain wheel 610, driven by the driving chain 609, is firmly connected with a coupling sheave 630 provided with clutch engagement holes 631 to cooperate with pins 637. The wheel 610 and the coupling sheave 630 are together freely'rotatable on the shaft 611.

' If a coupling electromagnet 632 is energized by the de pression of one of the forward or backward push buttons 602 or 603, then the pins 637 on a half coupling 636 are introduced into the holes 631 of the coupling sheave 6590 provided at the front end of the drawer mounting 630 by means of a clutch fork 633 operating through a Y fork joint 634 and a slip ring 635. The half coupling 636 is slidably keyed to the shaft 611 which thus becomes driven through the half coupling. A pushing out or pulling in movement of the drawer takes place according to the direction of rotation of the chain wheel 610 given it by the selected forward or backward button. When the button is released and the energisation of the electromagnet 632 thereby ended, a spring 633 brings the clutch fork 633 back into its original position and uncouples the shaft 611. Simultaneously with the sideways shifting of the coupling element 636 when uncoupling, brake shoes 645 are pressed against a brake drum 639 by brake levers 640 which are hinged to a boss 641 whereby the shaft 611 and the operated drawer are stopped instantly. The boss 641 is held against rotation by a retaining arm 642 engaging in an aperture in a plate 643. When the electromagnet 632 is energised the levers 640 are attracted inwards by springs 644 and the brake shoes 645 are thereby released from the drum 639.

FIG. 3 shows also the guide elements for the drawer 613, namely a housing rail 646 with an extension carriage 647.

FIG. 4 shows in sectional end elevation how the other drawers can be driven also by thedriving chain 609 by means of additional chains 648 and 649. For this purpose there are provided an additional chain wheel 649' (FIG. 3) rigidly connected to the chain wheel 610 and chain wheels 650, 651 and 652 driven by the chains 648 and 649 and loosely mounted on the appropriate shafts for the other drawers.

For the prevention of recoil of the drawers when they are pushed into their fully in position bulfers 653 are provided, each consisting of a cylinder in which a piston 654 can move to and fro. The cylinder is closed except for a small aperture which can be regulated by a regulating screw 655. The regulation is effected so that as much air is able to escape from the cylinder as is required when the drawer is pushed back into its final position, in order to avoid a recoil. If the drawer is pushed out, then the piston is again brought forward by means of a weak spring 656 whereby air is again sucked into the cylinder. Ball catches 657 retain the'drawers in the fully closed position;

FIG. 5 shows a circuit diagram for the switches and electromagnets. In the closed position of the drawers, switches 658a, 658b, 6580, placed at the back end of the drawer mounting are open and other switches 659a, 65912,

are closed. It now one of the buttons 602 for pushing out a drawer is pressed,the contacts U, V of the appropriate push button are closed thereby completing the circuit to the motor as well as to the corresponding drawer operating electromagnet 632a, 632b, 6320. In this event the coupling halves 619 and 623 which determine rotation of the shaft 607 in the direction for outward drawer movement, are coupled together by the spring 622. As soon as the drawer leaves its fully inward position the corresponding switch 658 closes. When the drawer is pushed out to its full length, the corresponding switch 659 opens and thereby breaks the current to the motor 606 and to the corresponding electromagnet 632. Thus the drawer comes to a standstill.

If the proper return button 603 for bringing back the drawer is now pressed, the contacts 1:, y, z of the button are closed, and not only are the circuits of the motor 606 and of the appropriate electromagnet 632 closed again; but also the electromagnet 62 0 is excited. Thereby the coupling 625, 626 is clutched in (simultaneously disconnecting the coupling 619, 623) and-as explained abovethe direction of rotation of the shaft 607 is reversed so that the drawer is now pushed in. At the commencement of the inward movement of the drawer the corresponding switch 659 closes again. When the drawer reaches its fully closed position the corresponding contact switch 658 opens.

As can be seen from the switch diagram any of the other drawers can be pulled out or pushed back again independently of one another at any time and regardless of the momentary position of any other drawer, without these movements interfering with one another. Thus it is possible to pull out the drawer into a certain position and to leave it in that position and yet operate any other drawer independently of it. The'end switches 658 and 659 have closed circuit contacts and are arranged as limit switches. They are operated by an arm or the like mounted at the back end of the drawer.

As can be seen from FIG. 4, current carrying rails 660a, 660b, 6600 are provided on which are arranged press switches 661 with normally closed contacts adjustable along the rails as desired. These press switches are intended to be placed at spaced intervals corresponding to inside divisions of the drawer into difierent compartments (or groups of cards contained in them). Each drawer has a switch operating rail 663 which keeps open the contacts of each switch for as long as they are engaged and depressed by it. As each switch is released by the rail its contacts close and thereby transmit current to a small electric bulb placed under the appropriate opening 604 (FIG. 1) in the table top. The further the drawer is pushed out and the more compartments are thus brought into the field of sight and reach of the expert worker, the more bulbs light up. In this way it is possible to control the drawers accurately from the keyboard and to bring the section of the drawer which has to be dealt with into reach. The current for the small bulbs is supplied from a transformer at a low voltage.

Two more small electric bulbs are placed below the desk openings 605, their purpose being to identify the forward and return keys 602, 603 in front of them. For example the one bulb can light up green, then the other can only light up red if one of the return keys is operated. For this three special switches are provided which are operated simultaneously with the stop switches 658a, 658b, 6580 already described above and in exactly the. same way as these.

FIG. 3 shows the guidance of the drawerin connection with the carriage 647. The carriage at each side has mounted on it chain wheels 670 which engage with stationary guide chains 671, supported by the bottom part of the rail 646. The chain wheels 670 also engage upwardly with drawer chains 673 fixed laterally to angle rails 672 on each side of the drawer. By the chain wheels 670 and the chains 671 and 673 a mechanically operated guidance is assured between the carriage and the drawer. During this movement the carriage moves half the distance which the drawer travels.

FIG. 6 shows an example of the application of the present invention to a drawer, cabinet or cupboard as used for register and card index purposes. The arrangements of the motor, the driving gear for forward and backward movement and the corresponding clutch, as well as the independent drawer drive with its corresponding clutch and braking device are the same as previously the parts being identified by the same reference numbers, so further description of them is unnecessary. The drawing shows the difierent parts of the cabinet in perspective and is partly broken away in order to show the mechanical device clearly.

In FIG. 6 only deviations from the previous construction are that in place of a cog wheel and rack below the bottom of the drawer there is provided an endless chain 690 which is driven by a chain wheel 691 on shaft 611. This endless chain passes round a chain wheel 692 on spindle 693. The endless chain 692 is secured to the bottom of the drawer at its far end for example to angle 694.

This driving method, by means of an attached chain or something similar, allows for a convenient arrangement of the drawer couplings and braking device and the other parts which belong thereto. In the case of the present example, these parts are placed behind the drawers. Obviously they can be placed above the top drawer or below the bottom drawer, whereby, with the aid of further chain connections the impulse of the separate drawers is provided by means of the endless chain.

In the same way, as detailed here, the present arrangement can be adapted for the described writing desk, that is to say, the coupling and braking devices or other parts can be positioned backwardly instead of near the front end of the drawer, and so be out of the way of the operator.

The same motor can also work several other drawer cupboards, which may be placed either side by side or behind each other.

As FIG. 7 shows, each drawer front panel 674 is fitted to the drawer 613 with the insertion of a spring 675-. Threaded pins 676 of the drawer handle 677 reach through the front panel 674 and through a reinforcement 678 provided on the front part of the drawer 613, carry the spring 675 and hold the rear end of the spring with the help of a cover screw 679 and a nut 680. Through this yieldable arrangement of the front of the drawer injuries are prevented if persons by carelessness in pushing in the drawers get themselves, e.g. their fingers, caught between the front of a drawer and the structure of the table. In addition damage to the mechanism is obviated in the event of some object getting in between the front of the drawer and the structure of the table. For this purpose the whole drawer front can alternatively be made of a yieldable material.

What I claim is:

1. In a desk, cabinet or the like, equipment for automatically extending and retracting drawers, said equipment comprising the combination of an electromotor, transfer means, drive means and coupling means individual to each of the drawers; said electromotor driving a shaft carrying a first chain wheel in fixed relation thereto; each of said coupling means comprising a primary shaft and an output shaft, each of the primary shafts carrying a second chain wheel in fixed relation thereto; at least one endless chain operatively arranged as a transfer means to provide a driving connection between said first chain wheel and said second chain wheels; each of said coupling means also comprising an electromagneticaily operated half coupling slidably keyed to the output shaft of the coupling means, said half coupling when energized engaging a coupling sheave fixed on said primary shaft; a cog-wheel fixed on each of said output shafts, said cog wheels positioned beyond the drawers intermediate the side edges thereof, a rack mounted to the bottom of each drawer in a line of symmetry intermediate the side edges of said drawer, said cog-wheels meshing continuously with said racks to form said drive means.

2. The equipment set forth in claim 1 in which there is a braking means associated with each of coupling means, each of said braking means comprising a brake drum fixed on said output shaft and brake shoes arranged to engage said brake drum; said brake shoes being fixed against rotation, brake levers connecting said brake shoes to said half couplings so that said brake shoes engage said brake drum upon deenergization of the coupling means and disengage said brake drum when the coupling means is energized.

3. The equipment set forth in claim 1 in which a reverse gearing is arranged between said first shaft and the output shaft of said electromotor, said electromotor being of the unidirectional type, said gearing comprising an electromagnetically operated slip ring having two primary half couplings; said slip ring being slidably keyed on said first shaft; said two half couplings arranged to engage each one of two other half couplings fixed at output gear wheels of said gearing provided for selectively rotating said first shaft in clockwise direction and a counterclockwise direction, respectively. 7

4. Apparatus according to claim 1 wherein the front panels of the drawers or the like are made yieldable, for example by being mounted yieldably on the drawers, to avoid injury or damage should an object be trapped between a drawer front panel and the main structure on closing a drawer.

5. Apparatus according to claim 1 wherein the drawer front panels are themselves made of a flexible elastic material.

References Cited in the file of this patent UNITED STATES PATENTS 1,778,857 James Oct. 21, 1930 2,174,582 Hudon Oct. 3, 1939 2,185,763 DeLisle Jan. 2, 1940 2,187,012 Brenner Jan. 16, 1940 2,312,325 Earle Mar. 2, 1943 2,369,664 Froelich Feb. 20, 1945 2,386,520 Watson Oct. 9, 1945 2,504,629 Bertello Apr. 18, 1950 2,621,995 Zenner Dec. 16, 1952 2,796,308 Knittel June 18, 1957 2,829,022 Lewis Apr. 1, 1958 

